The present invention relates to a mounting apparatus for mounting a mirror-type deflection apparatus, i.e., a galvanomirror which controls the direction of a luminous flux used in an optical device such as an optical scanner or the like or used in a data recording/reproducing apparatus which records/writes data with respect to an optical recording medium such as an optical disk drive, postscript type disk drive, phase change disk drive, CD-ROM, DVD, optical card, or the like, by adjusting the inclination of the mirror-type deflection apparatus with respect to a fixed member to which the deflecting apparatus is mounted.
Conventionally, a small-size galvanomirror is used in various types of optical devices stated above. If the galvanomirror is mounted to the optical device of this type, it is required to adjust the inclination or the like of the mirror with respect to the light axis of entering light or the like and to accurately position the mirror. As a mounting apparatus for mounting the galvanomirror with the inclination of the mirror adjusted, various types of apparatuses are used. Since the above-stated optical device is strictly required to be small, a mounting apparatus provided with a spherical supporting surface is often used.
According to this mounting apparatus, a spherical supporting surface is formed on the main body, that is, on the base member of the galvanomirror and a bearing seat surface of, for example, spherical shape which abuts on the supporting surface is formed at a fixed member such as a carriage and a frame to which the galvanomirror is mounted. While the supporting surface abutting on the bearing seat surface, the galvanomirror is fixed. During or after mounting, the supporting surface is slid with respect to the bearing seat surface, thereby adjusting the inclination of the galvanomirror in an arbitrary direction, such as, about two axes perpendicular to each other and thereafter fixing the galvanomirror. The mounting apparatus of this type is simple in structure and can be made small, so that the apparatus is appropriate as a small-size galvanomirror mounting apparatus for the optical device stated above.
The front surface side of the galvanomirror serves as an optical path of the optical device. Obviously, therefore, the mounting apparatus cannot be arranged on the front surface side of the galvanomirror. For that reason, the conventional galvanomirror mounting apparatus is provided on the back surface of the mirror.
According to a galvanomirror apparatus disclosed by Jpn. UM Registration Publication No. 2536274, a spherical abutment portion is formed on the back surface of the yoke of the galvanomirror and a concave portion is formed on the front surface of a retainer. The abutment portion abuts on the concave portion, thus fastening the yolk and the retainer using three adjusting screws. In addition, the retainer is structured to be attached to the side surface of the vertical wall portion of a housing. While loosening the adjusting screws, the abutment portion is slid to the concave portion and the angle and position of the mirror are adjusted. Thereafter, the adjusting screws are fastened to thereby fix the yoke.
The conventional structure stated above, however, has the following drawbacks. That is, the housing and the like of the optical device are, in many cases, manufactured integrally by, for example, die-casting and a container section into which the optical components such as the galvanomirror are inserted and mounted is, in many cases, formed to be opened in the direction perpendicular to or crossing the optical path of the optical device. Due to this, if the abutment portion for adjusting the mounting position is formed on the back surface side of the galvanomirror as stated above, the retainer or the like is required to be mounted on the side surface of the vertical wall portion of the container section of the housing.
Due to the need to make the housing of the optical device small, the dimensions of the container section cannot have allowance for the outer dimensions of the optical components to be contained in the container section. Owing to this, after inserting the galvanomirror into such a narrow container section, the galvanomirror has to be mounted on the side surface of the vertical wall portion of the housing while adjusting the position. Thus, working efficiency greatly, disadvantageously deteriorates.
Furthermore, to provide a small-size apparatus, it is preferable that the concave portion is directly formed in the inner surface of the housing, that the galvanomirror-side abutment portion abuts on the concave portion and that the galvanomirror is directly mounted in the housing. Nevertheless, the housing is normally manufactured by die-casting as stated above. The concave portion cannot be, therefore, formed on the side surface of the vertical wall portion, that is, the metal mold leaving direction.
For those reasons, there is no choice but to adopt the structure in which the retainer is provided, a concave portion is provided at the retainer and the retainer is attached on the side surface of the vertical wall portion of the housing as in the above-stated conventional technique. As a result, the resultant structure is complicated, the number of parts increases, the dimensions of the mounting structure become greater, and the optical device is disadvantageously prevented from being made smaller.